E.i. Dupont De Nemours and Company

George R Coraor

Harold L Jackson

Frederick W Mader

Process for continuously transferring heat to a moving band of solid material, for example, a textile, a film, particles, or any shaped or unshaped article, the band preferably comprising a disperse dyeable synthetic polymer, for example, a polyester or polyamide, said process comprising passing the band through a substantially enclosed purging-drying region containing the superheated condensable vapor of a liquid having an atmospheric pressure boiling point of less than 120.degree. C., thence immediately thereafter through a substantially enclosed, heat-transfer region containing the superheated condensable vapor of a fluorocarbon having a fluorine to carbon atom ratio of at least 1.5, a solubility parameter of not more than 6.5 and a molecular weight of at least about 300, the pressure in the heat transfer region being no greater than that in the purging-drying region, thence immediately thereafter through a substantially enclosed purging region containing dry steam, the pressure in the purging region being no less than that in the heat-transfer region, and thereafter recovering the band of material, said process characterized by efficient heat transfer resulting from rapid convective movement of superheated fluorocarbon in the heat-transfer region and by minimum loss of such vapor to the atmosphere.

Process for continuously transferring heat to a moving band

Process for substantially quantitatively removing and recovering a volatile, organic, water-immiscible wetting liquid from a solid material which is wet therewith, which process comprises intimately contacting the solid material first with the superheated vapor of a water-immiscible, organic stripping liquid and thereafter with dry steam, said contacting taking place in an environment substantially free of noncondensable gas, condensing the mixture of organic vapor and steam to form a two-phase liquid mixture consisting of liquid organic phase and liquid water phase, and separating the liquid organic phase and the liquid water phase.

Process for recovering volatile organic liquids

Non-aqueous, atmospheric pressure, batch exhaust process for applying and fixing a disperse dye or brightening agent on a disperse dyeable synthetic polymer, for example, a polyester, in the form of a fiber, fabric or film, said process providing good exhaust and rapid fixation of dye and agent and comprising: A. immersing the polymer in a bath containing a dispersion comprising a liquid, organic continuous phase, a dispersing agent having dispersing activity in the continuous phase and at least one member of the group consisting of disperse dye and brightening agent, said continuous phase being a non-solvent for the dye or brightening agent; B. distillatively removing the continuous phase from the bath and replacing same, at a rate which is volumetrically proportional to the rate of removal of the continuous phase, with a liquid fluorocarbon which is miscible with the continuous phase and has a fluorine to carbon atom ratio of at least 1.5, a solubility parameter of no greater than 6.5 and a boiling point at 760 mm. pressure at least as high as the glass transition temperature (Tg) of the polymer and at least 10.degree. C. higher than that of the continuous phase; C. heating the polymer to at least its Tg and maintaining it at this temperature until the dye or agent is fixed on the polymer; and D. recovering polymer having dye or agent fixed thereon.

Growing community of inventors

Wilmington, DE, United States of America

George R Coraor